The National Information Infrastructure (NII) is far more than leased lines and routers. It encompasses significant underlying facilities and links, networking technologies from an array of vendors, regional and local facilities and equipment, and protocols at several levels. It runs through switching centers, wiring closets, manholes, campus backbones, microwave links, RS422/449 connections, muliplexors, etc. In the future, it will be possible to seamlessly broadcast and receive digital signals among interoperable cable, telephone, satellite and data networking systems. In the meantime, this is a period of transition in which both the possibilities and the interactions of providing services using these systems must be explored in various combinations.

Accomplishments

Equipment, software and services provided by industry were used to construct and staff the Network Services Operations Center (NSOC) at MIT in Cambridge, MA to support the production and delivery of NMIS projects. Within the NSOC, a special Digital Video Facility (DVF) was set up and used to produce the digital interactive multimedia and experimental multimedia services for the various NMIS initiatives. The NSOC was staffed by a full-time, networked multimedia engineer, systems programmer and technical staff to support the storage and network delivery of multimedia services. The staff initially operated under the direction of MIT/CAES and then, later in the project, also under co-direction with MIT/CECI.

Early in the NMIS project, an experimental infrastructure was created at the NSOC which included experimental multimedia servers, routers and switches (including satellite and cable links). To support this effort, IBM provided multimedia servers without charge which were deployed at Dartmouth and MIT to support multimedia development and testing. The servers were two IBM RS/6000 rack-mounted digital media servers with 80 GB of on-line storage each.

The NSOC's strategic location of video production facilities adjacent to the MIT cable head-end with a satellite link allowed experiments in various combinations of broadcasting and receiving of digital and analog signals via telephone, broadband, cable, terrestrial broadcast video and satellite video distribution networks respectively.

Future Directions

A variety of new technologies are now either now or soon going to be available in the NSOC. These include the addition of a Duplex/Optibase Showsite Card which supports low-band-width encoding of MPEG-1[21], an IBM video Access Node which encodes MPEG-2, an IBM streaming video server, and a robotic tape library with at least a terabyte of online storage. A critical component for improving delivery of multimedia information services using the Internet is moving past the current limit on the NMIS Project's connection through MIT's network (10 Mbps). Ideally, a direct and dedicated connection will be established to allow direct connections at speeds of up to ten times greater (100 Mbps.). In addition, CAES and CECI have installed an ATM network. These capabilities will all add exciting new experimental encoding and delivery options. In addition, CAES is building a comprehensive technology-enabled learning center which will include the integration of old and new NSOC capabilities with a new 45 seat tiered amphitheater for distance learning, a teaching studio to help teachers improve their distance learning techniques, and a flexible electronic learning studio (expected completion of all three components is 1998). One crucial capablity included in these new facilities will be support for end to end digital production processes designed to totally eliminate analog production bottlenecks.